• Title/Summary/Keyword: replacement cycle

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A Study of Optimal path Availability Clustering algorithm in Ad Hoc network (에드 혹 네트워크에서 최적 경로의 유효성 있는 클러스터링 알고리즘에 관한 연구)

  • Oh, Young-Jun;Lee, Kang-Whan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.278-280
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    • 2012
  • We are propose the position of the node context-awareness information and the validity of the head node in the path according to the clustering how to elect one of the energy efficiency ECOPS (Energy Conserving Optimal path Schedule) algorithm. Existing LEACH algorithm to elect the head node when the node's energy probability distribution function based on the management of the head node is optional cycle. However, in this case, the distance of the relay node status information including context-awareness parameters does not reflect. These factors are not suitable for the relay node or nodes are included in the probability distribution, if the head node selects occurs. In particular, to solve the problems from the LEACH-based hierarchical clustering algorithms, this study defines location with the status context information and the residual energy factor in choosing topology of the structure adjacent nodes. ECOPS algorithm that contextual information is contributed for head node selection in topology protocols. The proposed ECOPS algorithm has the head node replacement situations from the candidate head node in the optimal path and efficient energy conservation that is the path of the member nodes. The new head node election show as the entire node lifetime and network management technique improving the network lifetime and efficient management the simulation results.

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Effects of Sulfur Substitution on Chemical Bonding Nature and Electrochemical Performance of Layered LiMn0.9Cr0.1O2-xSx

  • Lim, Seung-Tae;Park, Dae-Hoon;Lee, Sun-Hee;Hwang, Seong-Ju;Yoon, Young-Soo;Kang, Seong-Gu
    • Bulletin of the Korean Chemical Society
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    • v.27 no.9
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    • pp.1310-1314
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    • 2006
  • Sulfur-substituted $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$ $(0\;\leq\;x\;\leq\;0.1)$ layered oxides have been prepared by solid state reaction under inert atmosphere. From powder X-ray diffraction analyses, all the present lithium manganates were found to be crystallized with monoclinic-layered structure. Electrochemical measurements clearly demonstrated that, in comparison with the pristine $LiMn_{0.9}Cr_{0.1}O_2$, the sulfur-substituted derivatives exhibit smaller discharge capacities for the entire cycle range but the recovery of discharge capacity after the initial several cycles becomes faster upon sulfur substitution. The effect of the sulfur substitution on the chemical bonding nature of $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$has been investigated using X-ray absorption spectroscopic (XAS) analyses at Mn and Cr K-edges. According to Mn K-edge XAS results, the trivalent oxidation state of manganese ion remains unchanged before and after the substitution whereas the local structure around manganese ions becomes more distorted with increasing the substitution rate of sulfur. On the other hand, the replacement of oxygen with sulfur has negligible influence on the local atomic arrangement around chromium ions, which is surely due to the high octahedral stabilization energy of $Cr^{+III} $ ions. Based on the present experimental findings, we have suggested that the decrease of discharge capacity upon sulfur substitution is ascribable to the enhanced structural distortion of $MnO_6$ octahedra and/or to the formation of covalent Li-S bonds, and the accompanying improvement of cyclability would be related to the depression of Mn migration and/or to the pillaring effect of larger sulfur anion.

Fluctuation of Tidal Front and Expansion of Cold Water Region in the Southwestern Sea of Korea (한국 남서해역에서 조석전선의 변동과 저수온역 확장기작)

  • Jeong, Hee-Dong;Kwoun, Chul-Hui;Kim, Sang-Woo;Cho, Kyu-Dae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.289-296
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    • 2009
  • The appearance and variation of cold water area and its expansion mechanism of tidal front in the south western coast of Korea in summer were studied on the basis of oceanographic data(1966-1995), satellite images from NOAA and SeaWiFs and numerical model. Cold water appearance in southwestern field of Jindo was due to the vertical mixing by strong tidal current. Tidal front where horizontal gradient of water temperature was more than $0.3^{\circ}C$/km parallels to contours of H/$U^3$ parameter 2.0~2.5 and the outer boundary of cold water region corresponds with contours of the parameter 2.5~3.0 in the southwestern sea of Korea during the period between neap and spring tides. The position replacement of tidal front formed in the study ares varies in a range of 25~75km and cold water region extends about 90km. These suggest that the magnitude of variation of frontal position and cold water area was proportionate to the tidal current during lunar tidal cycle. Moreover, it was estimated that the southwestward expansion of cold water region was derived from the southwestward tide-induced residual currents with speed more than 10cm/s.

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Research on the usage of oral hygiene devices and the general knowledge, attitude on oral health care in the orthodontic patients (교정환자의 구강건강관리에 관한 지식도와 태도 및 구강위생용품 사용실태)

  • Min, Hee-Hong;Na, Eun-Joo;Jun, Ji-Hean;Park, Young-Nam
    • Journal of Korean society of Dental Hygiene
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    • v.12 no.2
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    • pp.399-407
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    • 2012
  • Objectives : Purpose of this research is to determined the general knowledge on oral health and the usage of oral hygiene products in the orthodontic patients and try to provide an appropriate oral hygiene products for the patients. Methods : Orthodontic patients who visited a dental clinic in Daejeon were selected and data from 352 patients were collected. Questionnaire based on survey was conducted from 1st of March to 30th in 2011 and all the data was analysed by using SPSS statistical program (VER 15.0). Frequency analysis, $x^2$ test, T-test and the amount of diurnal variance analysis (one-way ANOVA) were also used. After that, scheffe's post-test method was conducted. Results : According to the general characteristics of oral health care knowledge score was $2.87{\pm}0.60$, the attitude score was $2.96{\pm}0.57$. toothbrush replacement cycle were less than 3 months (p=0.007, p=0.000) and frequency of brushing one day more than three times higher in patients with knowledge to help attitude. according to the sex, age, and duration of orthodontic treatment with oral hygiene devices of usage was higher in the calibration toothbrush usage, awareness was higher in the interdental toothbrushes. according to the type of orthodontic devices from the oral hygiene devices usage, removable group was the orthodontic toothbrush and electric toothbrush group were highest in the 'unknown', the fixed group was orthodontic toothbrush(67.3%) and electric toothbrushes(40.8%) was higher in the usage. Patients who used oral hygiene devices such as orthodontic tooth brush, interdental brush, electric toothbrush, water pik and fern solution showed wider knowledge on oral health care and oral hygiene devices compared to patients who answered as does not aware of oral hygiene devices and never used these products before. Conclusions : Orthodontic patient's oral health attitudes, knowledge, and oral hygiene devices usage are the general characteristics of the highest in the orthodontic toothbrush usage, awareness was higher in the interdental brush. Water pik and fern solution, rubber and gingival interdental stimulator turned massage does not use or low. Based on results from research, overall orthodontic patients who visited a dental clinic had low awareness and usage of oral hygiene devices. Therefore, it is required to educate general publics and the orthodontic patients and also promote the importance of usage of oral hygiene devices.

Comparisons of the Change in Soft Contact Lenses Parameters and the Cleaning Efficiency after Eyeliner Deposition (아이라이너 침착에 의한 소프트 콘택트렌즈 파라미터의 변화 및 세척효과의 비교)

  • Park, Mijung;Kim, Sa Hyun;Ku, Bo Kyoung;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.107-115
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    • 2013
  • Purpose: This study was conducted to investigate the change of soft contact lens parameters after eyeliner deposition and compare the cleaning efficiency and the recovery rate of lens parameters by different cleaning methods. Methods: The eyeliner was deposited on three types of soft contact lenses made of different materials for 1 hour, 4 hours and 6 hours and those lenses were washed by the eyeglasses ultrasonic cleaning and by hands. The changes in visible light transmittance, diameter and surface of those lenses were compared before and after cleaning of the lens. Results: The visible light transmittance of soft contact lenses decreased along with the deposition time of eyeliner. The patterns of the eyeliner deposition on soft contact lens appeared differently depending on the physical properties of the lens material. Thus, the largest eyeliner deposition was found on narafilcon A lens. The diameters of hilafilcon B and etafilcon A lenses were decreased, however, the diameter of narafilcon A lens was increased. The cleaning efficiency of the eyeliner deposition was greater with the multipurpose solution by hands than with the eyeglasses ultrasonic cleaner. However, the recovery of lens parameters such as the lens diameter, visible light transmittance and lens surface due to the eyeliner deposition to its original state was limited. Conclusions: From these results, it is suggested to minimize eye makeup when wearing soft contact lens. Furthermore, the reduced wearing time and shorter cycle of lens replacement may be needed by considering a change of lens parameter when the repeat eye makeup is applied.

A Study on Concept Design of Customized Gripper for Assembly Process of IT Products (IT 제품의 조립 공정 맞춤형 그리퍼 개념 설계에 관한 연구)

  • Kim, Hyeon-Guk;Hwang, Soon-Woong;An, Bo-Young;Heo, Jun-Hyung;Choi, Youn-Sung;Shin, Kyoo-Sik;Han, Chang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.644-652
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    • 2018
  • This paper describes the conceptual design of a customized gripper for the assembly process of IT products, which has a relatively short and regular product replacement cycle. The grippers that are used in the manufacturing field are mostly composed of one to two degrees of freedom and they can only handle one object, not multiple ones. Cost is also an important factor. If it were possible to develop a gripper suitable for the assembly process quickly and easily, some of the difficulties involved in its automation caused by the frequent changes of product and process could be solved. The assembly process utilized for this research is defined and described as the procedure and method of the process analysis due to the confidentiality of the manufacturer. We used an axiomatic design to derive the functional requirements and design parameters of the gripper used for the tablet PC assembly process. We proposed a design method for the conceptual design of the gripper by determining these parameters. For the feasibility study, a specific process was selected and the progress of the gripper design was described as an example. Although there have been studies on the design guidelines for grippers, their considerations are too general and their degree of freedom is too high. This paper defines the function of the gripper based on the assembly process of the IT products, which allows their production to be streamlined and automated. In this research, we attempted to produce a design that reflects the assembly process, not just one that enables objects to be held.

Characterization of Biomass-Based Foam Structures for Home-Meal-Replacement Containers (가정간편식 용기용 바이오매스 기반 발포구조체의 특성에 관한 연구)

  • Kim, Inae;Kim, Sumin;Kambiz, Sadeghi;Han, Jeonggu;Hwang, Kiseop;Kwon, Hyukjoon;Kim, Yongsu;Yoo, Seung Ran;Seo, Jongchul
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.26 no.2
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    • pp.77-83
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    • 2020
  • A series of foamed plastic sheets containing biomass (as HMR container) were developed via different foaming process temperatures, and their density, porosity, WVTR, and pore morphology were evaluated. Thermal stability of samples during re-heating the food in oven, change in morphology, density, porosity, and WVTR were investigated using a simulated thermal shock process according to MIL-STD-883E assay. As such, the pore size of samples was generally increased with increasing temperature of the foaming process. It can be explained that as foaming temperature increased, the viscosity of molten resins and the repulsive force against pore expansion decreased. In addition, an increase in the thermal shock cycle reduced the pore size and WVTR, while density increased because high temperature treatment that softened the sheet matrix was followed by a low temperature incubation, which contracted the matrix, thereby changing the physical and morphological properties of samples. However, an insignificant change in density was observed and WVTR tended to be decreased, indicating that as-prepared foamed plastic sheets could be used as a high thermal stable container for HMR application. Therefore, it found that the properties of newly developed HMR containers containing biomass were dependent on the foaming process temperature. Moreover, to better understanding of these newly developed containers, further investigations dealing with foaming process temperature based on various food items and cooking conditions are needed.

Effect of Heifer Frame Score on Growth, Fertility, and Economics

  • Senturklu, S.;Landblom, D.G.;Perry, G.A.;Petry, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.1
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    • pp.69-78
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    • 2015
  • A non-traditional forage-based protocol was employed to evaluate replacement heifer growth, fertility, and economics between small frame (SF, 3.50; n = 50) and large frame (LF, 5.56; n = 50) heifers using three increasing gain growth phases. Preceding an 85 d growing-breeding period (Phase 3; P3) the heifers were managed as a common group for Phases 1 and 2 (P1 and P2). During P1, heifers grazed common fields of unharvested corn and corn residue (total digestible nutrients [TDN] 56%) with supplemental hay. For P2, heifers grazed early spring crested wheatgrass pasture (CWG; TDN 62%) that was followed by the final P3 drylot growing and breeding period (TDN 68%). Small frame heifers were lighter at the end of P1 in May and at the start of P3 breeding in August (p = 0.0002). Percent of mature body weight (BW) at the end of P1 (209 d) was 48.7% and 46.8%, respectively, for the SF and LF heifers and the percent pubertal was lower for SF than for LF heifers (18.0% vs 40.0%; p = 0.02). At breeding initiation (P3), the percentage of mature BW was 57.8 and 57.2 and the percentage pubertal was 90.0 and 96.0 (p = 0.07) for the SF and LF heifers, respectively; a 5-fold increase for SF heifers. Breeding cycle pregnancy on days 21, 42, and 63, and total percent pregnant did not differ (p>0.10). In drylot, SF heifer dry matter intake (DMI) was 20.1% less (p = 0.001) and feed cost/d was 20.3% lower (p = 0.001), but feed cost/kg of gain did not differ between SF and LF heifers (p = 0.41). Economically important live animal measurements for muscling were measured in May and at the end of the study in October. SF heifers had greater L. dorsi muscle area per unit of BW than LF heifers (p = 0.03). Small frame heifer value was lower at weaning (p = 0.005) and the non-pregnant ending heifer value was lower for SF heifers than for the LF heifers (p = 0.005). However, the total development cost was lower for SF heifers (p = 0.001) and the net cost per pregnant heifer, after accounting for the sale of non-pregnant heifers, was lower for SF heifers (p = 0.004). These data suggest that high breeding efficiency can be attained among March-April born SF and LF virgin heifers when transitioned to a more favorable May-June calving period through the strategic use of grazed and harvested forages resulting in a lower net cost per pregnant SF heifer.

VOC/HAPs Emission Characteristics & Adsorption Evaluation for Paint Products in Busan Area (부산지역 페인트제조시설의 VOC/HAPs 배출특성 및 흡착능 평가)

  • Song, Bok-Joo;Lee, Seung-Min;Cho, Gab-Je;Cho, Jeong-Gu;You, Pyung-Jong;Kim, Gi-Gon
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.5
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    • pp.316-325
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    • 2012
  • In this study, we suggested adequate control technology by analyzing emission process and main chemical of VOC/HAPs generated from four paint factories in Busan area. And we estimated whether Kapok fiber, which is a natural material, can be commercially used for an absorbent by testing adsorption ability. As a result of this sturdy, above 60% of VOC/HAPs was volatilized and dispersed inside the working place without conducting control system of facilities during manufacturing paints. Concentration profile of VOC/HAPs, which is volatile naturally outside the factories, is surveyed above 70% at Toluene, Ethylbenzene, and Xylene. And a result of evaluation of odor attribution level about the component whose Odor Threshold is known, it is estimated that major cause material of A, B, C factories is Toluene and that of D factory is m/p-Xylene. And that result presented design arguments such as facilities specifications, activated carbon filling volume, and replace cycle of activated carbon as control technology. Also, that result presented emission process improvement such as adsorption of central-controlled ventilation device, installation of inlet flenge, and potable cleaning process. The rate of pollutant adsorption of Kapok fiber, which is natural material, is indicated about 91.9%, 66.7%. That result validated the possibility as replacement of activated carbon.

Properties of Cementless Loess Mortar Using Eco-Friendly Hardening Agent (친환경 무기질 고화재를 사용한 무시멘트 황토모르타르의 특성)

  • Jung, Yong-Wook;Kim, Sung-Hyun;Lee, Dong-Gyu
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.3 no.4
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    • pp.355-365
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    • 2015
  • This study examined the fluidity and strength properties, water resistance, durability, and freeze-thaw of cementless loess mortar using an eco-friendly hardening agent. The experimental result indicates that 28 days compressive and flexural strength of the loess mortar was increased regardless of the weathered granite soil and loess mixture ratio as the replacement ratio of the hardening agent increases. The strengths were significantly increased until 14 days regardless of the hardening agent, while the effect on the strengths increasement was relatively low after 14 days. Thus, the strength development of loess mortar concrete was found to be faster than that of the normal concrete. In addition, when the hardening agent of 10% was used, the average flexural strength was 1.7MPa which is insufficient compared to the 28-day flexural strength of 4.5MPa for the paving concrete. However, the flexural strengths of the loess mortar concrete using the hardening agents of 20% and 30% were 4.0MPa and 5.3MPa, respectively. Thus, the hardening agent need to be at least 20% so that the loess mortar can be used for paving concrete. The experiment for water resistance shows that the repeated absorption and dry reduced mass regardless of the mixing ratio of the loess. The maximum length change also decreased with increasing the substitution rate loess mixture ratio and the hardening agent. The result of the freeze-thaw resistance test indicates that the relative dynamic modulus of elasticity at 300 cycle freeze-thaw with the hardening agents of 20% and 30% were 75% and 79%, relatively. Thus, the hardening agent of at least 20% is required to obtain the relative dynamic modulus of elasticity of 60% for the loess mortar.